Role of dynamic strain aging on low cycle fatigue and crack propagation of type 316L(N) stainless steel

Tensile, strain-controlled low cycle fatigue (LCF), and crack propagation tests were conducted at RT and 600 °C in air atmosphere for type 316L(N) stainless steels containing 0.04% N and 0.10% N. Nitrogen increased tensile strength without the reduction of elongation. LCF life increased with nitrogen content and the magnitude of increase was higher at 600 °C than at RT. Fatigue crack propagation rate increased with temperature but decreased with the addition of nitrogen. Nitrogen retarded dynamic strain aging (DSA) and decreased crack propagation. The larger increase of LCF life at 600 °C than that observed at RT with the addition of nitrogen was attributed to the retardation of DSA by the addition of nitrogen.